Sheet-gripping mechanism for printing presses.



N G. A. FRIESS.

SHEET GRIPPING MECHANISM FOR PRINTlNG PRESSES.

- 7 APPLICA ION FILED FEB.1Z; 1916. I 1,293,749. Patented Feb. 11, 1919.

2 SHEET,SS,H F I NNQN G. A. FRIESS.

SHEET GRIPPING MECHANISM FOR PRINTING PRESSES.

APPLICATION FILED FEB. 12, I9I6.

1 ,293,749, 7 Patented Feb. 11, 1919.4

2 SHEETSSHEEI 2.

GUSTAV A. FRIESS, OF CHICAGO, ILLINOIS.

SHEET-GRIPPING MECHANISM FOR PBINTINGr-PRESSEEI;

Specification of Letters Patent.

Patented'Feb. 11, 1919.

Application filed. February 12, 1916. Serial No. 77,839.

To all whom it may concern Be it known that I, GUSTAV A. Fnrnss, subject of the Emperor of Germany, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Sheet-Gripping Mechanism for Printing-Presses; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it ap'pertains to make and use the same.

This invention has'for its object to provide novel sheet-gripping means for the tympan cylinders of printing presses, and has for its particular object to provide coacting sheet grippers which will grip the sheet at a point beyond the face of the impression cylinder, and will then automaticallyrecede to a point below such surface so as to present no proj ecting portions which may contact with and injure the printing cylinder of the press.

A further object of the invention is to provide sheet-gripping means of the character defined which, by reason of their projection beyond the surface of the cylinder, are better positioned to receive the sheets to be printed for the purpose of feeding the same to the printing face of the printing cylinder.

The invention consists in the features of construction and combination of parts hereinafter fully described and particularly claimed.

In the accompanying drawings illustrating a preferred embodiment of the invention Figure 1 is a fragmentary radial longitudinal section through the tympan cylinder of a printing press and a portion of the frame thereof equipped with sheet-gripping mechanism embodying my invention.

Figs. 2, 3 and 4 are fragmentary detail transverse sections through the tympan cylinder and sheet-gripping mechanism showing the latter in three different posithe rotation of the tympan an arc equal substantially the radii of Figs tions during cylinder through to the angle between and 4.

Fig. 5 is a fragmentary detail section through a portion of the frame showing a cam and a portion of gripper-operating mechanism for actuating the sheet-gripping means.

Figs. 6 and 7 are fragmentary detail transverse sections through the tympan cylinder showing a portion of the sheet-gripping mechanism in two difierent positions.

Fig. 8 is a fragmentary detail end elevation of a portion of the tympan cylinder showing in section a projection for actuating the sheet-gripping means.

Referring now to said drawings, A indicates the tympan or impression cylinder of a printing press which is provided contiguous to its ends with radial recesses B in which guide blocks C are radially movable. The said guide blocks are integral with and disposed at the ends of an anvil bar D constituting a portion of the sheet-gripping means, both said-blocks and said anvil members being normally held at the outer limit of their radial movement by means of' the compression springs E bearing onthe inner faces'thereof. Suitable stops F are provided for limiting the outward movement of the blocks C, said springs E being adapted to normally hold said blocks in engagement with said stops.

A shaft G s ournaled at its ends in said blocks C, and is equipped between its ends with a plurality of gripper fingers H, the hubs I of which are rigid with the said shaft G. Contiguous to the bearings for said shaft G the latter is provided with a pair of arms J in the outer ends of which the heads K are pivotally secured. The guide recesses B of the cylinder communicate with the longitudinal recess or pocket L extending the entire length of the cylinder A, said gripper fingers and said arms J being adapted to project or extend into said groove or recess L. On the longitudinal wall of the said recess L farthest removed from the nearest adjacent side wall of the grooves 13 there are mounted projections M provided with pivoted heads similar to the heads K, and between said heads K and M helical compression springs O are interposed, said springs 0 being adapted to throw the shaft G to either of two positions, toward which it is primarily turned by means of the throw-over member 1? on said shaft G and the pins or projections Q and R on the press frame.

Each of said blocks Ccarries an antifriction roller S in the path of which are cam-surfaces T on the projections U of the press frame, said cam surfaces being disposed to efiect an inward or depressing movement of the blocks G as said portion of the cylinder A containing. said gripper 7 through its longer arc.

mechanism approaches the surface of the printing cylinder N, and maintaining said blocks depressed until said portion of said cylinder A has passed the opposed portion of said cylinder N. g

The said projections U constitute inverted channels, the lower edges of the inner flanges of which are provided with said cam surfaces T and the'inner face of the other flange of one of which carries the two'pins or projections Q, and R, respectively, which extend toward the inner flange of said channel. The throw-over arm P on the shaft Gr is a channeled member and said pins or projections Q and R are adapted to enter opposite ends of the same, being disposed in the paths of the opposite mouths of said channel for engaging in the same in the usual and well-known manner to turn said shaft G through arcs of a length sufficient to cause the springs O to throw said shaft through the balance of the arc requisite to effect engagement of the sheet between the gripper fingers H and the anvil member D, and to throw-said-gripper fingers to the position shown in Fig. 4 and there hold the same While the cylinder A rotates Thus the gripper mechanism is actuated at regular intervals in the usual well-known manner but is moved bodily by independently operative mechanism from its outer to its inner position and back while engaged with a sheet.

I claim as myinvention:

In a printing press, a tympan cylinder equipped with a sheet gripping mechanism, comprising an anvil member carried by the cylinder and arranged for radial movement relatively to the cylinder, anti-friction rollers rotatably mounted on the ends of the anvil member, internal stationary cam surfaces on the press frame in the paths of said rollers and adapted to force the anvil mem: ber inwardly, compression springs beneath the ends of the anvil member normally tending to hold the anvil member 'at the outer limit of its movement and a shaft mounted in bearings in the ends of the anvil member and movable therewith, gripper fingers for cooperation with the anvil mem ber carried by said shaft, and means for yieldingly holding the gripper fingers in contact with the anvil member as the same is moved radially.

In testimony whereof I have signed my two subscribing wit-V name in presence of nesses.

l/Vitnesses:

R. W, Lo'rz, M. M. BOYLE.

Copies of this patent may be. obtained for five cents each, Icy-addressing the Commissioner of Patents, Washington, D. G. 1 

